This invention relates generally to test equipment for radio apparatus and more particularly to means for self testing modern multichannel radio receivers.
A typical multichannel radio receiver which includes digital frequency synthesizing circuitry may have a frequency range of, for example, from 30 to 80MHz with a multitude of frequency channels equally spaced 25kHz apart. It becomes desirable that the operator be provided with an indication of whether or not his receiver is sensitive and receives signals within any of the designated channels. Accordingly, a simple test circuit is disclosed herein which provides both amplitude and frequency modulated carriers simultaneously at each and every channel frequency of the receiver for self testing the receiver with which it is incorporated.